My boat has an internal main halyard that exits on the left side of the mast, but I'd like to switch it over to the right side. Can I do this without droping the mast?
Dan Dickison responds:
Thanks for coming to us with your question about moving halyards. Actually, what you're asking about is a pretty simple procedure on most boats, depending upon the exit box configuration at the lower end of the mast. And it can almost always be done without unstepping the mast, but again it depends on what you have to work with.
There are two things that you have to worry about when making such a change. The first is chafe to the halyard in its new position, and the second is the possibility of the halyard fouling some internal electrical wiring in its new position. With most spars, the electrical wiring is housed in conduit tubing or contained by wire clips as it ascends to the masthead, so you shouldn't have too much of problem there unless your boat is pretty old.
The chafe is the real issue with the change you're contemplating because the new route for the halyard isn't the route that the initial rigger or boatbuilder had in mind. There's a slight chance that the ends of bolts or other protrusions inside the mast might be in the way of the proposed route on the right side of the mast and thus produce chafe.
So, here's what you do. Get a piece of old doublebraid line that's roughly equal in diameter to the halyard that you plan to move, and attach a small-diameter messenger line to it that is about five feet longer than the height of the mast. (I recommend sewing them together with waxed sail repair thread, but you can tie them if you want so long as your knot is streamline. If you do tie them, be sure to wrap the tie with rigging tape so that it can't come untied in the process.) Then you'll want to have someone hoist you up to the masthead in a bosun's chair so that you can feed that messenger line down in such a way that it approximates the new route for the mainsheet. (You'll probably have to weight the end of the messenger line with a small nut or other item to ensure that it descends and doesn't foul on the way down the inside of the mast.) The idea is to get the spare line in the position that the mainsheet will occupy on the right-hand side of the mast and then pull it up and down and over the sheaves at each end (approximating the action of the halyard when it raises and lowers the mainsail) to ensure that there is no chafe. If that's the case, then you're ready to swap the halyard over.
Now that you have a messenger line run through the right-hand side at the base of the mast, you just have to attach the main halyard and pull it through and you should be done. While you're still up in the bosun's chair, see if you can reave a short messenger line or even a short length of wire over the mainsail halyard sheave and then attach it to the longer messenger line that you used to test for chafe. That messenger line should still be attached to the spare doublebraid that is run out the right side of the mast down on deck. Use the short line or wire to fish the longer messenger line out so that it runs over the mainsail halyard sheave just as you want the mainsail halyard to do. Once you've done that, you can either return to the deck to finish the job (taking the messenger line with you), or do it from aloft. All you need to do now is attach the tail end of the mainsail halyard to the longer messenger line (and sew it, or tape it like you did before) and then pull it back through the new route. Once you pull the messenger line through it will pull the main halyard through and you'll have finished the job. Just disconnect the messenger line from the halyard and you're done.
I suspect that some of these steps might seem a little complicated since you don't have the benefit of pictures or diagrams, but it's really a pretty simple process.
Here's wishing you the best of luck with this project.